1. Field of the Invention
The present invention relates to an electronic device having a display device. More particularly, the present invention relates to a method and apparatus to detect coordinates in an electronic device having a pen-based display device.
2. Description of the Related Art
Typically, electronic devices such as a TeleVision (TV), a portable phone, a computer, an electronic blackboard, a tablet, an e-book reader, and a smart phone adopt a keyboard, a keypad, a mouse, and so forth for interfacing with a user. However, with the recent development trend of small-size electronic devices with enhanced portability, User Interface (UI) methods have evolved accordingly. Major UI methods include a touch screen input scheme in which a user applies an input by directly touching a screen with a finger or a touch pen and a motion recognition scheme in which a user applies an input by a gesture.
The touch screen input scheme requires inputs such as a handwritten input on a display. For example, a resistive-type touch screen input scheme enables input through an input means like a stylus pen. However, as a capacitive-type touch screen input scheme has gained in popularity, handwriting is difficult to input.
In the touch screen input schemes, an input is determined by recognizing patterns predefined on a display using an electronic pen. Specifically, patterns formed on the display are recognized by means of the electronic pen having a camera, the position of the electronic pen is detected based on the recognized patterns, and an input is determined based on the detected position value. That is, an area of the display pointed by the electronic pen is captured along the direction of the pen point of the electronic pen through the camera and preset patterns are detected from the captured image. Thus, the position pointed by the electronic pen or a command is recognized based on the detected patterns.
FIG. 1 illustrates exemplary patterns formed on a display in an electronic pen-based input scheme according to the related art.
Referring to FIG. 1, pixels 101, sub-pixels 103, and Black Matrices (BMs) 105 are defined on a display. Each pixel 101 is divided into sub-pixels 103 representing Red (R), Green (G) and Blue (B), respectively. Adjacent sub-pixels and adjacent pixels are separated from each other by BMs 105.
According to the electronic pen-based input scheme illustrated in FIG. 1, changed sub-pixels 107 are obtained by applying preset patterns to pixels or sub-pixels. A position or motion on the display may be determined by recognizing changed sub-pixels 107 using an electronic pen. However, the changed sub-pixels 107 cause performance degradation of the display. That is, the changed sub-pixels 107 may distort represented colors or affect brightness or sharpness of the display in relation to the performance of the display. Moreover, when the electronic pen recognizes a wrong pattern, it is not easy to detect or correct the error.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.